CREATE OR REPLACE FUNCTION notify_app_after_table_insert()
RETURNS TRIGGER AS
$BODY$
    BEGIN
        PERFORM pg_notify('devices', json_build_object('old', row_to_json(OLD), 'new', row_to_json(NEW))::text);
        RETURN new;
    END;
$BODY$
LANGUAGE plpgsql;

CREATE TRIGGER trigger_notify_app_after_table_insert
AFTER UPDATE
ON devices
FOR EACH ROW
EXECUTE PROCEDURE notify_app_after_table_insert();


// NodeJS
pool.connect().then((client) => {
          console.log('REGISTERING LISTENERS FOR NOTIFICATIONS')
          client.query('LISTEN devices')
          client.on('notification', (msg) => {
            console.log('MESSAGE', msg)
          })
        })